The Codebreakers

From mosquitoes to potatoes, genomics unlocks DNA secrets

"The toll of insect-borne diseases is staggering," says Dennis Knudson,
professor of bioagri-cultural sciences and pest management. "Worldwide,
hundreds of millions of people are infected with malaria at this very moment.
Three billion people  more than half the world population  are at
risk for contracting the disease. Millions died from it last year, and that's
just one disease of many carried by insects, ticks, and their brethren."

Knudson has been a faculty member at Colorado State University for the past
12 years. His research interests have ranged from virology to genomics and from
insects to plants. His insect pest of interest is the yellow fever mosquito,
Aedes aegypti. Knudson and his colleague, Susan Brown, trace their interests
in mosquitoes and infectious disease to their work at the Yale Arbovirus Research
Unit, Yale University School of Medicine. In 1998, Janice Stephens, a Colorado
State graduate, joined the team with her expertise in plants, histology, and
cytogenetics. Undergraduates Mario Carmosino and Philip Stephens round out the
research team.

The team is studying the molecular and genetic pathways that enable mosquitoes
to transmit parasitic diseases. They hope to determine why some mosquitoes transmit
the disease and others do not. Such knowledge will open the door to new ways
to control these infectious diseases.

By now most people have heard of DNA fingerprinting, widely used in criminal
trials. Less well-known, but just as important, are other tools used in genomics:
fluorescent in situ hybridization (or FISH) physical mapping, DNA sequencing,
polymerase chain reaction (PCR), and bioinformatics. "The chance to learn
all these new procedures as well as using my own expertise is what attracted
me to be part of the team," says Stephens.

Knudson, Brown, and Stephens have established many of these sophisticated tools
here at Colorado State. With them, they have found the general region on the
mosquito chromosome that makes mosquitoes likely disease carriers. The bad news
is that there are about two million sequences in this region. So, there's a
lot more to do before they identify the gene that allows mosquitoes to do their
dirty work.

While Knudson's research group focuses on mosquitoes, their overall goals are
much broader. "What we learn from the mosquito project is directly applicable
to agriculture," says Knudson."For example, we can use the same methods
to find the genes that help a plant resist a particular disease."

Through collaborations with colleagues in soil and crop sciences, pathology,
animal sciences, bioagricultural sciences and pest management, and microbiology,
Knudson's group is applying its tools to the study of barley genetics, bacterial
ring rot in potatoes, wheat resistance to Russian wheat aphid, and livestock
projects. Brown says, "Keeping the different systems straight can be quite
a job, but seeing our technology make contributions in other research areas
is rewarding."

The Knudson team is part of the Arthropod-Borne Infectious Disease Laboratory
(AIDL) at Colorado State. They also collaborate with scientists at the Centers
for Disease Control laboratory in Fort Collins and the Arthropod-Borne Animal
Disease Research Laboratory in Laramie, Wyo. Thanks to major grant funding from
the National Institutes of Health and with additional support from the MacArthur
Foundation, the U.S. Department of Agriculture, and the Colorado Agricultural
Experiment Station, Knudson and his team have purchased sophisticated equipment,
built labs, and established genomics tools previously unavailable at Colorado
State. These tools enrich the environment at the University through the team's
extensive collaborations.

Genomics may not seem relevant to our everyday lives, but it will profoundly
affect our future. Says Knudson, "Genomics will impact our lives as dramatically
as did the Industrial Revolution."